1. Technical Field of the Invention
The present invention generally relates to the telecommunications field and, in particular, to a cellular communications network and method that maintains a desired speech quality by determining whether or not to admit a new call within a serving cell based on the current speech quality in the serving cell and the current speech quality in other cells interfered with by the serving cell.
2. Description of Related Art
In order to improve the radio environment of today""s cellular communications networks, many operators utilize automated planning techniques (e.g., Adaptive Frequency Allocation) to assist with frequency planning and cell assignment decisions that help maintain speech quality by minimizing the interference. The current automated planning techniques are defensively designed and have large safety margins to ensure that xe2x80x9cgoodxe2x80x9d speech quality is maintained throughout the entire cellular telecommunications network.
Unfortunately, it is very expensive to use the current automated cell planning techniques to ensure that xe2x80x9cgoodxe2x80x9d speech quality is maintained throughout the entire cellular telecommunications network. In addition, the current automated cell planning techniques often increase the already high maintenance costs due to the large safety margins by requiring the addition of new cells that may not necessarily be required.
Accordingly, there is a need for a method and cellular communication network capable of maintaining xe2x80x9cgoodxe2x80x9d speech quality within a particular part of the network by determining whether or not to admit a new call in a serving cell based on the current speech quality in the serving cell and the current speech quality in other cells interfered with by the serving cell. This and other needs are satisfied by the cellular communications network and method of the present invention.
The present invention is a method and cellular communication network that maintains a desired level of speech quality by controlling the admission of a new call within a serving cell of the network. More specifically, the method includes the step of establishing speech quality values for a serving cell and at least one of a plurality of surrounding cells being interfered with by the serving cell. The method then operates to determine whether or not to admit the new call to the serving cell by utilizing the speech quality measure of the serving cell and the speech quality measure of the at least one surrounding cell in a predetermined manner (e.g., cell level approach, sub-cell approach and combined approach) so as to maintain the desired level of speech quality within the serving cell and the at least one surrounding cell.
In accordance with the present invention, there is provided a method and cellular communications network that maintains a desired level of speech quality by controlling the admission of new calls and handovers of ongoing calls to a serving cell.
Also in accordance with the present invention, there is provided a method and cellular communications network capable of reducing the large safety margins and high costs commonly associated with the current cell planning techniques.
Also in accordance with the present invention, there is provided a method and cellular communications network that determines whether or not to admit a new call based on a cell level approach, sub-cell level approach or a combined approach.
Further in accordance with the present invention, there is provided a method and cellular communications network capable of operating in accordance with any telecommunications standard that supports mobile assisted handovers such as, for example, the Global System for Mobile Communications (GSM) standard.